The present invention relates to systems and methods for control of power electronic applications, including their control over power lines by a CDMA (Code Division Multiple Access) DSSS (Direct Sequence Spread Spectrum) communication network, in particular for control system networks. The invention also relates to the control in close-loop of a number of lighting fixtures, or lamps within one fixture, by a single central ballast. The invention further relates to PLC (Power Line Carrier) communication control of large automation systems including HVAC (heating, ventilation, air-conditioning), security, fire alarm systems, etc. Existing PLC communication systems do not provide adequate and cost effective solutions to the control networks mentioned above.
The problem of controlling a number of fixtures or a number of lamps in one fixture by a single central ballast has been tackled for a long time by lighting engineers, with little success. In prior art, the control of all fixtures is typically done in open loop, by fixing one light level to all fixtures (having one feedback only), and by providing the power to the fixtures according to this parameter. The drawback of this approach is that the parameter variations between the lamps, the wiring, and the components at the level of the fixture, produce light dispersions that are intolerable to the eye. One example is the case of multiple fixture dimmable electronic ballasts (MFDEB), in which the power distribution from the central ballast to the individual fixture is not controlled in close-loop, and depends upon the length of the wiring and its characteristics. Another example is that of ballast that controls individually several lamps in one fixture.
There is therefore a need for, and it would be advantageous to have, methods and systems for advanced control of various power and other electronic systems. Moreover, it would be advantageous to control in close-loop, together or separately, a number of fixtures or a number of individual lamps by a single central ballast. Such a “central ballast control” would be beneficial in that it decreases the cost of the ballast per fixture, by having a single central high power ballast, and by distributing the power to several lighting fixtures or lamps. Furthermore, there is a need for an energy saving lighting system that can advantageously use such methods and systems.